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Editing: _process_win32_controller.py
"""Windows-specific implementation of process utilities with direct WinAPI. This file is meant to be used by process.py """ #----------------------------------------------------------------------------- # Copyright (C) 2010-2011 The IPython Development Team # # Distributed under the terms of the BSD License. The full license is in # the file COPYING, distributed as part of this software. #----------------------------------------------------------------------------- # stdlib import os, sys, threading import ctypes, msvcrt # Win32 API types needed for the API calls from ctypes import POINTER from ctypes.wintypes import HANDLE, HLOCAL, LPVOID, WORD, DWORD, BOOL, \ ULONG, LPCWSTR LPDWORD = POINTER(DWORD) LPHANDLE = POINTER(HANDLE) ULONG_PTR = POINTER(ULONG) class SECURITY_ATTRIBUTES(ctypes.Structure): _fields_ = [("nLength", DWORD), ("lpSecurityDescriptor", LPVOID), ("bInheritHandle", BOOL)] LPSECURITY_ATTRIBUTES = POINTER(SECURITY_ATTRIBUTES) class STARTUPINFO(ctypes.Structure): _fields_ = [("cb", DWORD), ("lpReserved", LPCWSTR), ("lpDesktop", LPCWSTR), ("lpTitle", LPCWSTR), ("dwX", DWORD), ("dwY", DWORD), ("dwXSize", DWORD), ("dwYSize", DWORD), ("dwXCountChars", DWORD), ("dwYCountChars", DWORD), ("dwFillAttribute", DWORD), ("dwFlags", DWORD), ("wShowWindow", WORD), ("cbReserved2", WORD), ("lpReserved2", LPVOID), ("hStdInput", HANDLE), ("hStdOutput", HANDLE), ("hStdError", HANDLE)] LPSTARTUPINFO = POINTER(STARTUPINFO) class PROCESS_INFORMATION(ctypes.Structure): _fields_ = [("hProcess", HANDLE), ("hThread", HANDLE), ("dwProcessId", DWORD), ("dwThreadId", DWORD)] LPPROCESS_INFORMATION = POINTER(PROCESS_INFORMATION) # Win32 API constants needed ERROR_HANDLE_EOF = 38 ERROR_BROKEN_PIPE = 109 ERROR_NO_DATA = 232 HANDLE_FLAG_INHERIT = 0x0001 STARTF_USESTDHANDLES = 0x0100 CREATE_SUSPENDED = 0x0004 CREATE_NEW_CONSOLE = 0x0010 CREATE_NO_WINDOW = 0x08000000 STILL_ACTIVE = 259 WAIT_TIMEOUT = 0x0102 WAIT_FAILED = 0xFFFFFFFF INFINITE = 0xFFFFFFFF DUPLICATE_SAME_ACCESS = 0x00000002 ENABLE_ECHO_INPUT = 0x0004 ENABLE_LINE_INPUT = 0x0002 ENABLE_PROCESSED_INPUT = 0x0001 # Win32 API functions needed GetLastError = ctypes.windll.kernel32.GetLastError GetLastError.argtypes = [] GetLastError.restype = DWORD CreateFile = ctypes.windll.kernel32.CreateFileW CreateFile.argtypes = [LPCWSTR, DWORD, DWORD, LPVOID, DWORD, DWORD, HANDLE] CreateFile.restype = HANDLE CreatePipe = ctypes.windll.kernel32.CreatePipe CreatePipe.argtypes = [POINTER(HANDLE), POINTER(HANDLE), LPSECURITY_ATTRIBUTES, DWORD] CreatePipe.restype = BOOL CreateProcess = ctypes.windll.kernel32.CreateProcessW CreateProcess.argtypes = [LPCWSTR, LPCWSTR, LPSECURITY_ATTRIBUTES, LPSECURITY_ATTRIBUTES, BOOL, DWORD, LPVOID, LPCWSTR, LPSTARTUPINFO, LPPROCESS_INFORMATION] CreateProcess.restype = BOOL GetExitCodeProcess = ctypes.windll.kernel32.GetExitCodeProcess GetExitCodeProcess.argtypes = [HANDLE, LPDWORD] GetExitCodeProcess.restype = BOOL GetCurrentProcess = ctypes.windll.kernel32.GetCurrentProcess GetCurrentProcess.argtypes = [] GetCurrentProcess.restype = HANDLE ResumeThread = ctypes.windll.kernel32.ResumeThread ResumeThread.argtypes = [HANDLE] ResumeThread.restype = DWORD ReadFile = ctypes.windll.kernel32.ReadFile ReadFile.argtypes = [HANDLE, LPVOID, DWORD, LPDWORD, LPVOID] ReadFile.restype = BOOL WriteFile = ctypes.windll.kernel32.WriteFile WriteFile.argtypes = [HANDLE, LPVOID, DWORD, LPDWORD, LPVOID] WriteFile.restype = BOOL GetConsoleMode = ctypes.windll.kernel32.GetConsoleMode GetConsoleMode.argtypes = [HANDLE, LPDWORD] GetConsoleMode.restype = BOOL SetConsoleMode = ctypes.windll.kernel32.SetConsoleMode SetConsoleMode.argtypes = [HANDLE, DWORD] SetConsoleMode.restype = BOOL FlushConsoleInputBuffer = ctypes.windll.kernel32.FlushConsoleInputBuffer FlushConsoleInputBuffer.argtypes = [HANDLE] FlushConsoleInputBuffer.restype = BOOL WaitForSingleObject = ctypes.windll.kernel32.WaitForSingleObject WaitForSingleObject.argtypes = [HANDLE, DWORD] WaitForSingleObject.restype = DWORD DuplicateHandle = ctypes.windll.kernel32.DuplicateHandle DuplicateHandle.argtypes = [HANDLE, HANDLE, HANDLE, LPHANDLE, DWORD, BOOL, DWORD] DuplicateHandle.restype = BOOL SetHandleInformation = ctypes.windll.kernel32.SetHandleInformation SetHandleInformation.argtypes = [HANDLE, DWORD, DWORD] SetHandleInformation.restype = BOOL CloseHandle = ctypes.windll.kernel32.CloseHandle CloseHandle.argtypes = [HANDLE] CloseHandle.restype = BOOL CommandLineToArgvW = ctypes.windll.shell32.CommandLineToArgvW CommandLineToArgvW.argtypes = [LPCWSTR, POINTER(ctypes.c_int)] CommandLineToArgvW.restype = POINTER(LPCWSTR) LocalFree = ctypes.windll.kernel32.LocalFree LocalFree.argtypes = [HLOCAL] LocalFree.restype = HLOCAL class AvoidUNCPath(object): """A context manager to protect command execution from UNC paths. In the Win32 API, commands can't be invoked with the cwd being a UNC path. This context manager temporarily changes directory to the 'C:' drive on entering, and restores the original working directory on exit. The context manager returns the starting working directory *if* it made a change and None otherwise, so that users can apply the necessary adjustment to their system calls in the event of a change. Examples -------- :: cmd = 'dir' with AvoidUNCPath() as path: if path is not None: cmd = '"pushd %s &&"%s' % (path, cmd) os.system(cmd) """ def __enter__(self): self.path = os.getcwd() self.is_unc_path = self.path.startswith(r"\\") if self.is_unc_path: # change to c drive (as cmd.exe cannot handle UNC addresses) os.chdir("C:") return self.path else: # We return None to signal that there was no change in the working # directory return None def __exit__(self, exc_type, exc_value, traceback): if self.is_unc_path: os.chdir(self.path) class Win32ShellCommandController(object): """Runs a shell command in a 'with' context. This implementation is Win32-specific. Example: # Runs the command interactively with default console stdin/stdout with ShellCommandController('python -i') as scc: scc.run() # Runs the command using the provided functions for stdin/stdout def my_stdout_func(s): # print or save the string 's' write_to_stdout(s) def my_stdin_func(): # If input is available, return it as a string. if input_available(): return get_input() # If no input available, return None after a short delay to # keep from blocking. else: time.sleep(0.01) return None with ShellCommandController('python -i') as scc: scc.run(my_stdout_func, my_stdin_func) """ def __init__(self, cmd, mergeout = True): """Initializes the shell command controller. The cmd is the program to execute, and mergeout is whether to blend stdout and stderr into one output in stdout. Merging them together in this fashion more reliably keeps stdout and stderr in the correct order especially for interactive shell usage. """ self.cmd = cmd self.mergeout = mergeout def __enter__(self): cmd = self.cmd mergeout = self.mergeout self.hstdout, self.hstdin, self.hstderr = None, None, None self.piProcInfo = None try: p_hstdout, c_hstdout, p_hstderr, \ c_hstderr, p_hstdin, c_hstdin = [None]*6 # SECURITY_ATTRIBUTES with inherit handle set to True saAttr = SECURITY_ATTRIBUTES() saAttr.nLength = ctypes.sizeof(saAttr) saAttr.bInheritHandle = True saAttr.lpSecurityDescriptor = None def create_pipe(uninherit): """Creates a Windows pipe, which consists of two handles. The 'uninherit' parameter controls which handle is not inherited by the child process. """ handles = HANDLE(), HANDLE() if not CreatePipe(ctypes.byref(handles[0]), ctypes.byref(handles[1]), ctypes.byref(saAttr), 0): raise ctypes.WinError() if not SetHandleInformation(handles[uninherit], HANDLE_FLAG_INHERIT, 0): raise ctypes.WinError() return handles[0].value, handles[1].value p_hstdout, c_hstdout = create_pipe(uninherit=0) # 'mergeout' signals that stdout and stderr should be merged. # We do that by using one pipe for both of them. if mergeout: c_hstderr = HANDLE() if not DuplicateHandle(GetCurrentProcess(), c_hstdout, GetCurrentProcess(), ctypes.byref(c_hstderr), 0, True, DUPLICATE_SAME_ACCESS): raise ctypes.WinError() else: p_hstderr, c_hstderr = create_pipe(uninherit=0) c_hstdin, p_hstdin = create_pipe(uninherit=1) # Create the process object piProcInfo = PROCESS_INFORMATION() siStartInfo = STARTUPINFO() siStartInfo.cb = ctypes.sizeof(siStartInfo) siStartInfo.hStdInput = c_hstdin siStartInfo.hStdOutput = c_hstdout siStartInfo.hStdError = c_hstderr siStartInfo.dwFlags = STARTF_USESTDHANDLES dwCreationFlags = CREATE_SUSPENDED | CREATE_NO_WINDOW # | CREATE_NEW_CONSOLE if not CreateProcess(None, u"cmd.exe /c " + cmd, None, None, True, dwCreationFlags, None, None, ctypes.byref(siStartInfo), ctypes.byref(piProcInfo)): raise ctypes.WinError() # Close this process's versions of the child handles CloseHandle(c_hstdin) c_hstdin = None CloseHandle(c_hstdout) c_hstdout = None if c_hstderr is not None: CloseHandle(c_hstderr) c_hstderr = None # Transfer ownership of the parent handles to the object self.hstdin = p_hstdin p_hstdin = None self.hstdout = p_hstdout p_hstdout = None if not mergeout: self.hstderr = p_hstderr p_hstderr = None self.piProcInfo = piProcInfo finally: if p_hstdin: CloseHandle(p_hstdin) if c_hstdin: CloseHandle(c_hstdin) if p_hstdout: CloseHandle(p_hstdout) if c_hstdout: CloseHandle(c_hstdout) if p_hstderr: CloseHandle(p_hstderr) if c_hstderr: CloseHandle(c_hstderr) return self def _stdin_thread(self, handle, hprocess, func, stdout_func): exitCode = DWORD() bytesWritten = DWORD(0) while True: #print("stdin thread loop start") # Get the input string (may be bytes or unicode) data = func() # None signals to poll whether the process has exited if data is None: #print("checking for process completion") if not GetExitCodeProcess(hprocess, ctypes.byref(exitCode)): raise ctypes.WinError() if exitCode.value != STILL_ACTIVE: return # TESTING: Does zero-sized writefile help? if not WriteFile(handle, "", 0, ctypes.byref(bytesWritten), None): raise ctypes.WinError() continue #print("\nGot str %s\n" % repr(data), file=sys.stderr) # Encode the string to the console encoding if isinstance(data, unicode): #FIXME: Python3 data = data.encode('utf_8') # What we have now must be a string of bytes if not isinstance(data, str): #FIXME: Python3 raise RuntimeError("internal stdin function string error") # An empty string signals EOF if len(data) == 0: return # In a windows console, sometimes the input is echoed, # but sometimes not. How do we determine when to do this? stdout_func(data) # WriteFile may not accept all the data at once. # Loop until everything is processed while len(data) != 0: #print("Calling writefile") if not WriteFile(handle, data, len(data), ctypes.byref(bytesWritten), None): # This occurs at exit if GetLastError() == ERROR_NO_DATA: return raise ctypes.WinError() #print("Called writefile") data = data[bytesWritten.value:] def _stdout_thread(self, handle, func): # Allocate the output buffer data = ctypes.create_string_buffer(4096) while True: bytesRead = DWORD(0) if not ReadFile(handle, data, 4096, ctypes.byref(bytesRead), None): le = GetLastError() if le == ERROR_BROKEN_PIPE: return else: raise ctypes.WinError() # FIXME: Python3 s = data.value[0:bytesRead.value] #print("\nv: %s" % repr(s), file=sys.stderr) func(s.decode('utf_8', 'replace')) def run(self, stdout_func = None, stdin_func = None, stderr_func = None): """Runs the process, using the provided functions for I/O. The function stdin_func should return strings whenever a character or characters become available. The functions stdout_func and stderr_func are called whenever something is printed to stdout or stderr, respectively. These functions are called from different threads (but not concurrently, because of the GIL). """ if stdout_func is None and stdin_func is None and stderr_func is None: return self._run_stdio() if stderr_func is not None and self.mergeout: raise RuntimeError("Shell command was initiated with " "merged stdin/stdout, but a separate stderr_func " "was provided to the run() method") # Create a thread for each input/output handle stdin_thread = None threads = [] if stdin_func: stdin_thread = threading.Thread(target=self._stdin_thread, args=(self.hstdin, self.piProcInfo.hProcess, stdin_func, stdout_func)) threads.append(threading.Thread(target=self._stdout_thread, args=(self.hstdout, stdout_func))) if not self.mergeout: if stderr_func is None: stderr_func = stdout_func threads.append(threading.Thread(target=self._stdout_thread, args=(self.hstderr, stderr_func))) # Start the I/O threads and the process if ResumeThread(self.piProcInfo.hThread) == 0xFFFFFFFF: raise ctypes.WinError() if stdin_thread is not None: stdin_thread.start() for thread in threads: thread.start() # Wait for the process to complete if WaitForSingleObject(self.piProcInfo.hProcess, INFINITE) == \ WAIT_FAILED: raise ctypes.WinError() # Wait for the I/O threads to complete for thread in threads: thread.join() # Wait for the stdin thread to complete if stdin_thread is not None: stdin_thread.join() def _stdin_raw_nonblock(self): """Use the raw Win32 handle of sys.stdin to do non-blocking reads""" # WARNING: This is experimental, and produces inconsistent results. # It's possible for the handle not to be appropriate for use # with WaitForSingleObject, among other things. handle = msvcrt.get_osfhandle(sys.stdin.fileno()) result = WaitForSingleObject(handle, 100) if result == WAIT_FAILED: raise ctypes.WinError() elif result == WAIT_TIMEOUT: print(".", end='') return None else: data = ctypes.create_string_buffer(256) bytesRead = DWORD(0) print('?', end='') if not ReadFile(handle, data, 256, ctypes.byref(bytesRead), None): raise ctypes.WinError() # This ensures the non-blocking works with an actual console # Not checking the error, so the processing will still work with # other handle types FlushConsoleInputBuffer(handle) data = data.value data = data.replace('\r\n', '\n') data = data.replace('\r', '\n') print(repr(data) + " ", end='') return data def _stdin_raw_block(self): """Use a blocking stdin read""" # The big problem with the blocking read is that it doesn't # exit when it's supposed to in all contexts. An extra # key-press may be required to trigger the exit. try: data = sys.stdin.read(1) data = data.replace('\r', '\n') return data except WindowsError as we: if we.winerror == ERROR_NO_DATA: # This error occurs when the pipe is closed return None else: # Otherwise let the error propagate raise we def _stdout_raw(self, s): """Writes the string to stdout""" print(s, end='', file=sys.stdout) sys.stdout.flush() def _stderr_raw(self, s): """Writes the string to stdout""" print(s, end='', file=sys.stderr) sys.stderr.flush() def _run_stdio(self): """Runs the process using the system standard I/O. IMPORTANT: stdin needs to be asynchronous, so the Python sys.stdin object is not used. Instead, msvcrt.kbhit/getwch are used asynchronously. """ # Disable Line and Echo mode #lpMode = DWORD() #handle = msvcrt.get_osfhandle(sys.stdin.fileno()) #if GetConsoleMode(handle, ctypes.byref(lpMode)): # set_console_mode = True # if not SetConsoleMode(handle, lpMode.value & # ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT)): # raise ctypes.WinError() if self.mergeout: return self.run(stdout_func = self._stdout_raw, stdin_func = self._stdin_raw_block) else: return self.run(stdout_func = self._stdout_raw, stdin_func = self._stdin_raw_block, stderr_func = self._stderr_raw) # Restore the previous console mode #if set_console_mode: # if not SetConsoleMode(handle, lpMode.value): # raise ctypes.WinError() def __exit__(self, exc_type, exc_value, traceback): if self.hstdin: CloseHandle(self.hstdin) self.hstdin = None if self.hstdout: CloseHandle(self.hstdout) self.hstdout = None if self.hstderr: CloseHandle(self.hstderr) self.hstderr = None if self.piProcInfo is not None: CloseHandle(self.piProcInfo.hProcess) CloseHandle(self.piProcInfo.hThread) self.piProcInfo = None def system(cmd): """Win32 version of os.system() that works with network shares. Note that this implementation returns None, as meant for use in IPython. Parameters ---------- cmd : str A command to be executed in the system shell. Returns ------- None : we explicitly do NOT return the subprocess status code, as this utility is meant to be used extensively in IPython, where any return value would trigger : func:`sys.displayhook` calls. """ with AvoidUNCPath() as path: if path is not None: cmd = '"pushd %s &&"%s' % (path, cmd) with Win32ShellCommandController(cmd) as scc: scc.run() if __name__ == "__main__": print("Test starting!") #system("cmd") system("python -i") print("Test finished!")
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